1. Field of the Invention
The present invention relates generally to portable drill assemblies mountable to a working surface and, more particularly, to a magnetically mountable portable drill assembly mountable to a working surface.
2. Description of the Related Art
Magnetically mountable portable drill assemblies (magdrills) are used extensively in the metal fabricating field for forming holes in various working surfaces or workpieces supported on the working surfaces where it is either impractical or inconvenient to move the workpiece or the working surface to a conventional drill press. Typically, magnetically mountable portable drill assemblies have an arbor coupled to a motor which is attached to a slide assembly. The slide assembly is mounted for vertical movement in relation to a magnetic base. A cutter is coupled to the arbor and a handle is typically used to rotate a gear which rectilinearly moves the slide assembly between a retracted position and an extended position to form a hole in a workpiece or working surface. Thus, to drill a hole, the entire motor, arbor, slide, and cutter must be slidably actuated in a vertical plane relative to the magnetic base.
Drilling a precision hole in a substantial workpiece or working surface such as a steel I-beam, pipe or plate, requires a relatively powerful electrical motor to maintain an acceptable rate of operation. Due to the strength and precision required to moveably support the entire motor, arbor, slide, and cutter, the drill assembly is relatively bulky and difficult to maneuver along a workpiece or working surface.
Accordingly, as the magnetically mountable portable drill assembly is moved to the workpiece or working surface, it is advantageous to provide the most portable and compact drill assembly possible. Additionally, as the drill assembly is operated in a construction environment, it is preferable that the drill assembly have a minimum number of exposed parts. The minimization of exposed parts improves the durability and the maintenance requirements of the drill assembly.
It is known to provide illumination for the magnetically mountable portable drill assembly. Typically, a light is mounted to an outer surface of the drill assembly. However, when the light is mounted above an upper end of the cutter of the drill assembly, it will cast a shadow where a pilot of the cutter meets the working surface. In addition, when the light is mounted to the outer surface of the drill assembly, it is susceptible to damage and interfere with positioning the drill assembly in tight spaces.
It is, therefore, desirable to provide a magnetically mountable portable drill assembly that has a light mounted below a cutting end of a cutter when the cutter is in a retracted position to provide better illumination during operation. It is also desirable to provide a magnetically mountable portable drill assembly that has a light mounted to a magnetic base. It is further desirable to provide a magnetically mountable portable drill assembly that has a light that is not exposed externally to allow the drill assembly to be mounted in tight spaces. It is still further desirable to provide a magnetically mountable portable drill assembly having a light which is compact, has a minimum number of exposed parts and is of a relatively light weight.